Remove hashed storage migration workers [Second minor release]

What does this MR do and why?

This MR deletes Hashed storage migration worker classes that are no-op and adds the corresponding migration to remove them.

This is the second minor release of !133394 (merged), as part of https://docs.gitlab.com/ee/development/sidekiq/compatibility_across_updates.html#removing-worker-classes.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #427497 (closed)